Aircraft Lighting System; Electrical Switch And Fuse Panel - Cessna 150 STANDARD Service Manual

TEMPERATURE
91 - 100°F
BUS VOLT AGE
13.8 - 14.1
13.7-14.0
13.6-13.9
The voltage regulator is adjustable but adjust-
ment on the airplane is not recommended. A
bench adjustment procedure is outlined in the
Cessna Alternator Charging Systems Service/
Parts Manual.
16-41. REMOVAL AND INSTALLATION (Refer to
figure 16-4).
a. Make sure that the master switch is off and dis-
connect the negative lead from the battery.
b. Remove the connector plug from the regulator.
c. Remove two screws holding the regulator on the
firewall.
d. To replace the regulator, reverse this procedure.
Be sure that the connections for grounding the alter-
nator, wiring shields and the base of the regulator
are clean and bright before assembly. Otherwise,
16-46. TROUBLE SHOOTING.
poor voltage regulation and/or excessive radio noise
may result.
16-42. AIRCRAFT LIGHTING SYSTEM.
16-43. DESCRIPTION. The aircraft lighting system
consists of landing and taxi lights, navigation lights,
anti- collision strobe lights, flaShing beacon light,
dame and instrument flood lights, control wheel map
light, compass and radio dial lights.
16-44. ELECTRICAL SWITCH AND FUSE PANEL.
16-45. DESCRIPTION. Thru 1975 models a remov-I
able electrical switch and fuse panel is located below
the shock panel. All electrical switches (except flap
switch), fuses, radio light rheostat, circuit breaker
and ignition switch are located in this panel. The
complete panel unit is removable from the instrument
panel by the removal of four screws. The panel unit
wiring is connected to the instrument panel wire har-
ness with quick disconnect mating connectors. New
type rocker switches with spade type slip-on terminals
and "push-in" plug button type mounting are introduced
in this panel. Beginning with 1976 models the fuses
I
are replaced with circuit breakers located on the
lower right hand side of the instrument panel. The
switch portion of the panel is no longer removable.
TROUBLE PROBABLE CAUSE REMEDY
LANDING AND TAXI LIGHT(S)
Short circuit in wiring.
1. Inspect fuse/circuit breaker.
OUT.
If
open, proceed to step 2.
If OK,
proceed to step 3.
I
Defective Wiring. 2. Test each circuit separately
until short is located. Repair
or replace wiring.
Defective switch.
3. Check voltage at lights with
master and landing and taxi light
switche s ON. Should read bat-
tery voltage. Replace switch.
LANDING AND/OR TAXI
Lamp burned out. 1. Te st lamp with ohmmeter or
LIGHT OUT.
new lamp. Replace lamp.
Open circuit in Wiring. 2. Test wiring for continuity.
Repair or replace wiring.
FLASHING BEACON DOES Short circuit in wiring.
1. Inspect fuse/circuit breaker.
NOT LIGHT.
If open, proceed to step 2. If OK,
proceed to step 3.
I
Defective Wiring. 2. Test circuit until short is lo-
cated. Repair or replace wiring.
Lamp burned ou~. 3. Test lamp with ohmmeter or
a new lamp. Replace lamp.
If
lamp is good, proceed to step 4.
Change 3
16-13